The present invention relates generally to the economical production of parts of synthetic material for spectacle frames, and more particularly of the face forming part of such frames.
As is well known, the term spectacle frame face is usually applied to that portion of the frame which is adpated to be equipped with ophthalmic lenses, excluding the side arms which are subsequently hinged to the face in order to enable the spectacles to be worn.
It has already been proposed to make spectacle frame faces of synthetic material.
However, the synthetic material usually employed for this purpose hitherto has most often been cellulose acetate.
A synthetic material of this kind cannot be moulded by casting and consequently only be machined or injection moulded.
The present invention has the object of permitting the production of faces of synthetic material by casting directly with the final shape of the faces, without the latter having to be subsequently subjected to a machining and/or polishing operation of any kind.
It is true that it is known for any product to be produced by moulding with the final shape required for it, by moulding the corresponding material between two half-moulds, usually by injection, and it is conceivable for a process of this kind to be applied indiscriminately to the moulding of faces of synthetic material for spectacle frames.
The present invention nevertheless proposes to permit such production at lowest cost by suitable selection of the material of which the half-moulds used are composed, of their structure, and of the moulding process to be employed.